Although squeeze bottle types sprayers have been used for many years, such sprayers were largely replaced for a long period of time by pressurized can dispensing systems. A major advantage to the use of pressurized cans is the nearly instantaneous spraying which occurs upon actuation. However, there has been an increasing concern over the harmful effects on the atmosphere of the propelling gases, such as fluorocarbons, which are used in such pressurized cans. In addition, pressurized can dispensing systems are relatively expensive to manufacture. Accordingly, squeeze bottle type sprayers and manual pump sprayers have become more prevalent in recent years.
Products which can be dispensed in the form of a spray can be easily atomizable liquids, such as water based materials, or viscous materials which are more difficult to atomize such as oil based materials. In the case of a pressurized can there is sufficient force available for mechanical means to break up liquid droplets into a fine spray. However, in squeeze bottle type sprayers the force required to break up droplets must be supplied manually, that is by squeezing the bottle. Therefore, it is much more difficult to achieve a high degree of atomization with such bottles.
Squeeze bottle type sprayers typically utilize a dip tube for directing liquid to a mixing chamber. Upon squeezing the bottle, air located above the liquid level is forced under pressure through a passage toward the mixing chamber where it impinges on a stream of the liquid in an effort to break up the liquid into droplets. The liquid is dispersed in a spray pattern through an orifice in the mixing chamber.
One major drawback to the use of conventional venturi squeeze bottles is that they do not always effectively atomize the liquid into a fine spray characterized by a symmetrical circular spray pattern and a symmetrical droplet size distribution. Furthermore, they do not always effectively atomize relatively viscous liquids.